class MyArray<T> {

}

public class Demo2 {
    public static void main(String[] args) {
    MyArray<Integer> obj = new MyArray<>();
    MyArray<String> obj2 = new MyArray<>();
    MyArray<?> obj3 = obj2;
    obj3 = obj;

    MyArray<? extends Number>
            obj4 = obj;
            //obj4 = obj2;

    MyArray<? super Integer>
        obj5 = obj;
        obj5 = new MyArray<Number>();
    }
}
